第6回東大京大コードゴルフ大会

hanoi.rb

class Hanoi
  STACK = { :A => 0, :B => 1, :C => 2 }
  BYTES = { :u8 => 0, :u16 => 1, :u32 => 2, :u64 => 3 }

  def pair(x, y)
    a, b = STACK[x], STACK[y]
    raise "" if a == b
    b -= 1 if a < b
    [a, b]
  end

  {
    :add => 0b000,
    :sub => 0b001,
    :mul => 0b010,
    :div => 0b011,
    :mod => 0b100,
    :or  => 0b101,
    :and => 0b110,
    :xor => 0b111,
  }.each do |name, xxx|
    define_method(name) do |from, to, size = :u8|
      yy, z = pair(from, to)
      nn = BYTES[size]
      @out << "001%03b%02b%01b%02b00000" % [xxx, yy, z, nn]
      @ip += 1
    end
  end

  def copy(from, to, size = :u8)
    xx, y = pair(from, to)
    nn = BYTES[size]
    @out << "0001%02b%01b%02b0000000" % [xx, y, nn]
    @ip += 1
  end

  def push(st, vvvvvvvv)
    xx = STACK[st]
    @out << "01%02b%08b0000" % [xx, vvvvvvvv]
    @ip += 1
  end

  def print(st)
    xx = STACK[st]
    @out << "00001%02b000000000" % [xx]
    @ip += 1
  end

  def pop(st, size = :u8)
    xx = STACK[st]
    nn = BYTES[size]
    @out << "000000%02b%02b000000" % [xx, nn]
    @ip += 1
  end

  def goto(name)
    @ip += 1
    @out << [name, @ip]
  end

  # def jmp(s, vvvvvvvvvvvvvv)
  #   @out << "1%01b%014b" % [s, vvvvvvvvvvvvvv]
  # end

  def iszero(st, size = :u8)
    xx = STACK[st]
    nn = BYTES[size]
    @out << "000001%02b%02b000000" % [xx, nn]
    @ip += 1
  end

  def label(name)
    @labels[name] = @ip
  end

  def exec(&block)
    @out = []
    @ip = 0
    @labels = {}
    instance_eval(&block)
    data = @out.map {|op|
      if op.is_a?(Array)
        name, from = op
        to = @labels[name]
        s = to - from < 0 ? 1 : 0
        vvvvvvvvvvvvvv = (to - from).abs
        op = "1%01b%014b" % [s, vvvvvvvvvvvvvv]
      end
      op.to_i(2)
    }.pack("S<*")
    File.write("./hanoi.out", data)
    puts "done: #{data.size} bytes"
  end
end


Hanoi.new.exec do
  pop :A, :u32
  32.times do |i|
    pop :A
    pop :A
    copy :A, :B
    pop :A
    xor :A, :B
    pop :B
    iszero :C
    goto [:L1, i]
      pop :C
      copy :A, :C
      pop :A
      pop :A
    goto [:L2, i]
    label [:L1, i]
      pop :A
      pop :A
      pop :C
      copy :A, :C
    label [:L2, i]
    pop :A
    pop :A
    pop :A
  end
  32.times do
    print :C
    pop :C
  end
end